Medical apparatus and method of making the same

Abstract

A catheter assembly includes a catheter having a proximal end and a distal end; an expandable device releasably attached to the catheter near the distal end; a generally tubular constraining sleeve extending around and compressing the device to an outer peripheral dimension suitable for endoluminal delivery; a tip fixedly secured to the distal end of the catheter; and a bridge member disposed between the tip and the expandable device so as to fill a gap therebetween as the catheter assembly is bent during endoluminal delivery of the expandable device to a treatment site.

What is claimed is: 
     
       1. A catheter assembly comprising:
 a catheter having a proximal end and a distal end; 
 an expandable device releasably attached to the catheter near the distal end, wherein the expandable device is maintained in a compressed state for endoluminal delivery; 
 a tip fixedly secured to the distal end of and generally coaxial with the catheter; and 
 a bridge member generally coaxial with the catheter and disposed in a gap between the expandable device and the tip, the bridge member being positioned distally to the expandable device and axially compressed between the tip and the expandable device such that the bridge member fills the gap between the expandable device and the tip with the expandable device maintained in the compressed state, such that the bridge member is configured to fill the gap between the expandable device and the tip during endolum inal delivery of the catheter assembly. 
 
     
     
       2. The catheter assembly as set forth in  claim 1 , further comprising a constraining sleeve that maintains the expandable device toward the outer peripheral dimension, wherein the bridge member is generally annular and includes a tapered surface radially engaging at least one of the expandable device and the constraining sleeve. 
     
     
       3. The catheter assembly as set forth in  claim 2 , wherein the tapered surface outwardly radially tensions at least one of the expandable device and the constraining sleeve. 
     
     
       4. The catheter assembly as set forth in  claim 3 , wherein the tapered surface is generally frustoconically shaped. 
     
     
       5. The catheter assembly as set forth in  claim 1 , wherein the catheter includes a lumen extending between the proximal and distal ends, the catheter assembly further comprising a tubular member extending through the lumen and having an end fixedly secured to the tip. 
     
     
       6. The catheter assembly as set forth in  claim 5 , wherein the tubular member includes a guidewire lumen extending axially therethrough. 
     
     
       7. The catheter assembly as set forth in  claim 6 , wherein the bridge member is generally annular and includes a bore which receives the tubular member therethrough. 
     
     
       8. The catheter assembly as set forth in  claim 5 , wherein a portion of the bridge member is fixedly secured to the tubular member so that a remaining portion of the bridge member is axially movable with respect to the catheter. 
     
     
       9. The catheter assembly as set forth in  claim 1 , wherein the bridge member fills the gap between the tip and the expandable device and provides a transition therebetween upon bending of the distal end of the catheter during deployment at an angled treatment site. 
     
     
       10. The catheter assembly as set forth in  claim 1 , wherein the bridge member is elastically deformed upon the axial compression between the tip and the expandable device. 
     
     
       11. The catheter assembly as set forth in  claim 10 , wherein the bridge member is axially movable with respect to the catheter. 
     
     
       12. The catheter assembly as set forth in  claim 11 , wherein at least a portion of the bridge member is fixedly secured to the tip or the catheter. 
     
     
       13. The catheter assembly as set forth in  claim 1 , wherein the catheter includes a guidewire lumen, and wherein the tip includes a bore generally axially aligned with the guidewire lumen to allow a guidewire to be fed through the catheter and the tip. 
     
     
       14. The catheter assembly as set forth in  claim 1 , further comprising a constraining sleeve that maintains the expandable device toward the outer peripheral dimension, wherein the bridge member includes a frustoconically shaped leading surface that faces the tip, which upon the axial compression between the expandable device and the tip provides a transition between the tip and the constraining sleeve. 
     
     
       15. The catheter assembly as set forth in  claim 1 , wherein the bridge member includes portions of varying durometer. 
     
     
       16. The catheter assembly as set forth in  claim 1 , wherein the bridge member includes a generally tubular shaped side wall and includes a wire frame coupled thereto to help the side maintain the gap between the tip and the device as the catheter assembly is bent during endoluminal delivery of the expandable device to a treatment site. 
     
     
       17. The catheter assembly as set forth in  claim 1 , wherein the bridge member fills the gap at an outer diameter of the catheter assembly. 
     
     
       18. The catheter assembly as set forth in  claim 1 , wherein the axial compression between the tip and the expandable device caused outward displacement of the bridge member to a desired outer profile. 
     
     
       19. The catheter assembly of  claim 1 , wherein the bridge member is disposed in the gap at a generally continuous diameter to fill the gap during endoluminal delivery of the catheter assembly. 
     
     
       20. A catheter assembly comprising:
 a catheter having a proximal end and a distal end; 
 an expandable device releasably attached to the catheter near the distal end; 
 a constraining sleeve that maintains the expandable device in a compressed state for endoluminal delivery; 
 a tip fixedly secured to the distal end of the catheter; and 
 
       a bridge member including a bore with the catheter within the bore, the bridge member being disposed in a gap distal to the expandable device and proximal to the tip, the bridge member being axially compressed between the tip and the expandable device such that a distal end of the expandable device is positioned proximal to a proximal end of the bridge member and the bridge member fills the gap at an outer diameter of the catheter assembly, such that the bridge member is configured to fill the gap at the outer diameter of the catheter assembly during endoluminal delivery of the catheter assembly. 
     
     
       21. The catheter assembly as set forth in  claim 20 , wherein the bridge member is elastically deformed from the axial compression between the tip and the expandable device causing outward displacement of the bridge member to fill the gap at the outer diameter of the catheter assembly.